XPS and optical studies of Xe+-implanted and annealed YSZ single crystals

Xe+ ion implantation with 200 keV was completed at room temperature up to a fluence of 1 × 1017 ion/cm2 in yttria-stabilized zirconia (YSZ) single crystals. Optical absorption and X-ray photoelectron spectroscopy (XPS) were used to characterize the changes of optical properties and charge state in the as-implanted and annealed crystals. A broad absorption band centered at 522 or 497 nm was observed in the optical absorption spectra of samples implanted with fluences of 1 × 1016 ion/cm2 and 1 × 1017 ion/cm2, respectively. These two absorption bands both disappeared due to recombination of color centers after annealing at 250 °C. XPS measurements showed two Gaussian components of O1s spectrum assigned to 〈Zr–O〉 and 〈Y–O〉, respectively, in YSZ single crystals. After ion implantation, these two peaks merged into a single peak with the increasing etching depth. However, this single peak split into two Gaussian components again after annealing at 250 °C. The concentration of Xe decreased drastically after annealing at 900 °C. And the XPS measurement barely detected the Xe. There was no change in the photoluminescence of YSZ single crystals with a fluence of 1 × 1017 ion/cm2 after annealing up to 900 °C.